In vehicular transmissions, such as but not limited to a dual clutch transmission, synchronizers are used to engage the different gears to achieve the different gear ratios. The synchronizers are moved by a synchronizer actuator fork that slides the synchronizer along a shaft into interlocking engagement with a gear. The timing, position and movement of the synchronizer actuator forks must be precisely controlled to obtain consistent, smooth shifts.
The synchronizer actuator forks may be controlled, for example, by a pressure solenoid that applies a fluid pressure to a first side of an actuator piston, and a flow solenoid disposed in series with the pressure solenoid and controlling fluid flow from a second side of the actuator piston. Movement of the actuator piston moves the synchronizer actuator fork. The magnitude of the fluid pressure applied to the first side of the actuator piston determines how fast the actuator piston moves, and thereby how fast the synchronizer actuator fork moves. An increase in the fluid pressure applied to the first side of the actuator piston increases the speed at which the synchronizer actuator fork moves, thereby decreasing the time required to move the synchronizer actuator fork from a disengaged start position into an engaged target position. In contrast, a decrease in the fluid pressure applied to the first side of the actuator piston decreases the speed at which the synchronizer actuator fork moves, thereby decreasing the time required to move the synchronizer actuator fork from the disengaged start position into the engaged target position.